In the late 18th and early 19th centuries the belief that man was not only a rational but also a reasonable animal reached its highest popularity. Its expression was to be found in William Godwin's "Political Justice." He asserted that man's opinions directed his behavior, and that any of the latter aberrations could be remedied by guidance. "Show me," he wrote, "in the clearest and most unambiguous manner that a certain mode of proceeding is most reasonable in itself, or most conducive to my interest, and I shall infallibly pursue that mode so long as the views you suggested to me continue present in my mind . . ." This rational approach strongly permeated the scientific thinking of that period, and found its finest expression and application in the medicine of the time.
However, around the same period Franz Anton Mesmer, a physician, initiated the modern era of hypnosis when he "sought to
Alouf FE. Applied Hypnosis and Positive Suggestion: In Medicine, Dentistry and Patient Care.. Arch Gen Psychiatry. 1966;14(1):111-112. doi:10.1001/archpsyc.1966.01730070113020